Hans th



Patented June 10, 1930 HANS T. BUCHERER, OF MUNICH,

GERMANY, ASSIGNORTO GENERAL ANILINE WORKS,

INC., OF NEW YORK, N. Y., A CORPORATION OF DELAWARE 2.3-BENZOCARIBAZOLE-1.4-Q UIlINONES AND PROCESS OF PREPARING THE SAME No Drawing. Application filed June 26, 1928, Serial No. 288,527, and in Germany June 3, 1926.

My present invention relates to 2.3-benzocarbazole-1.4-quinonesand'procss of preparing them.

It is known that the azo dyestufi's of the aryl-B-naphthylamine series are easily transv formed into the corresponding azines v by hydrolysis.

Since the 2.3-benzocarbazoles of the gen eral formula:

can be regarded as derivatives of the aryl-B- naphthylamines, it could be assumed that also the azo dyestuffs of the 2.3-benzocarbazole series of the general formula:

and derivatives thereof would undergo a similar transformation when heated to boilin temperature.

dyestufi's of the 2.3-benzocarbazole series of the general formula:

ow I have found that by heating the azo ones by heating them with a aryl These carbazole derivatives are at the same time derivatives of naphthoquinone. They can, as it had to be expected, easily be transformed into vats and can in fact be used as vat dyestufi's owing to their affinity to the textile fiber.

As regards the preparation of the azo dyestuffs of the 2.3-benzocarbazole series we have found that, instead of directly coupling a diazonium compound with the corresponding carbazole, these important intermediate products can also be obtained in another Way, namely by starting from the condensation" products obtainableby the action of an arylhydrazine-bisulfite mixture upon an azo, dyestufi' of ,B-napthylamine or ,8-naphthol. These condensation products have the following probable formula:

ing arylhydrazino-azo dyestuffs by heating them withfan alkali, on the other hand, probably by Way of the 2.3-benzocarbazole-azo dyestufi's, into the carbazoles of a-naphthoquinone, i. e. into 2.3-benzocarbazo1e-1.4-quindilute acid. The probable course of the reaction may be'illustrated by the. following structural formulae, the correctness of which has, however, not yet been ascertained:

latter can easily be separated from the un-.'

altered azo dyestuff owing to its insolubility in ammonia. The unaltered azo dyestuff can againbe transformed intothe a-naphthoquinone derivative after repeating the addition of bisulfite. a-naphthoquinone may also be obtained from the unaltered azo dyestufl without the addition of bisulfite.

As the azo dyestuffs of the carbazoles are apparently formed as intermediate products during the action of dilute acids upon the condensation products from an azo dyestuif and an aryl-hydrazine in presence of bisulfite, the 2.3-benzocarbazole-lA-quinones may also be prepared in another, and for the most 7 part simpler manner as described in the following example.

2. 10 grams of the yellow dyestufi', obtainable by the action of the mixture of henylhydrazine and bisulfite upon the azo yestuff from diazotized sulfanilic acid and ,B-naphthol, are heated on the water bath or in a reflux apparatus together with dilute hydrochloric acid or dilute sulfuric acid until the starting material has disappeared and 2.3-

- benzocarbazole-lA-quinone has been formed in its place.

The products obtainable according to the two preceding examples are identical and corres ond as regards their properties to the oxidatlon product of pheno-2.3-naphthocarbazole melting at 307 which has been described by Graebe and Knecht in Annalen s5 der Chemie Volume 202, page 13.

3. The-yellow intermediate product, obtainable by causing the azo dyestuff from diazotized sulfanilic acid and B-naphthol to react with asymmetric metaxylylhydrazme and bisulfite, is heated for some hours to boiling with dilute hydrochloric acid or sulfuric acid in the manner described in the preceding example. The dyestufi' thus obtained, namely the 2.3-benzo-6.8-dimethylcarbazolelA-quinone is purified in the usual manner. It crystallizes in the form of orange-red needles melting at over 300 C. It dissolves in sulfuric acid to a blue solution and yields a vat of a yellow coloration.

4. The yellow intermediate product obtainable by causingthe azo dyestuif from diazotized sulfanilic acid and ,B-naphthol to react with ,B-naphthylhydrazine and bisulfite is heated to boiling for several hours in a reflux apparatus together with sulfuric acid of about 50 per cent strength. The filtered crude dyestuif which is the 2.3-5.6-dibenzocarbazole-l.4-quinone, is purified by revatting it. The purified dyestufi' melts at over 300 C. It is soluble in concentrated sulfuric acid to a blue-solution and yields an orange vat.

The yield of 2.3-benzocarbazole-lA-quinones obtainable according to these examples depends among other things upon the concentration of the acid. There may for instance be used sulfuric acid of 50 per cent strength or hydrochloric acid of 25 per cent strength or other acids in other dilutions.

Instead of the azo dyestuff from sulfanilic acid and ,Bnaphth0l used in Examples 2, 3 and 4 other azo dyestuffs may be used, for example such in which substituted ,B-naphthols have been used instead of B-naphthol, so that it is possible by the process described in the said examples to prepare by synthesis quite generally 2.3-benzocarbazole-lA-quinones or substitution products thereof.

I claim:

1. In a process of preparing a 2.3-benzocarbazole-lA-quinone, the step which comprises heating a compound of the following general formula:

aryl X it x with a dilute acid.

2. 'In a process of preparing a 2.3-benzocarbazole-lA-qumone, the step which comprises heating a compound of the following general formula:

wherein X stands for any monovalent substituents and R for the group N=Naryl or NNHaryl (Y being a sulfo group),

with a dilute inorganic acid.

3. In a process of preparing a 2.3-benzocarbazole-1.4-quinone, the step which comprises heating a compound of the following general formula:

wherein X stands for any monovalent substituents and R for the group N=N aryl or NNHaryl (Y being a sulfo group),

with an excess of dilute sulfuric acid to boiling. o 4. In a process of preparing a 2 .3-benzocarbazole-L4-quinone, the step WhlCll comprises heating a compound of the following general formula If-NH-aryl wherein X stands for any monovalent substituents 'and Y for a sulfo group, with a dilute acid.

5. In a process of preparing a 2.3-benzocarbazole-lA-quinone, the step which comprises heating a compound of the following general formula:

X N a X wherein X stands for any Inonovalent substituents and Y for a sulfo group, with a dilute inorganic acid.

6. In a process of preparing a 2.3-benzocarbazole-L4-quinone, the step which comprises heating a compound of the following general formula:

x .N l X l aNsOsaNa wherein X stands for any monovalent substituents and Y for a sulfo -group, with an excess of dilute sulfuric acid to boiling.

7. A process of preparing a 2.3-benzocarbazole-lA-quinone which consists in heating with a dilute acid the product'of the follow- 'ing probable formula:

wherein X stands for any monovalent substituent and Y for a sulfo group.

8. A process of preparing 2.3-benzocarbazole-Ll-quinone which consists in heating with a dilute inorganic acidthe product of the following probable formula:

III-NH-nryl y with dilute sulfuric acid on the water bath until the starting material has disappeared.

10. As a new product, the compound of the followipg formula:

10 crystallizing in the form of orange-red needles meltin at over 300 (1, dissolvin in sulfuric aci to a blue solution and yiel ing a yellow vat.

In testimony whereof, I affix my signature.

HANS TH, BUCHERER. 

